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2. Depressurise the outlet side by opening the sam-
pling valve (vent valve on the AQA therm HES).
3. Slacken the compression spring
- Turn the adapter to the left (-) until it can go no
further.
The spring cap contains a compression spring.
Injuries may occur if the compression spring
jumps out of the cap.
- Make sure the compression spring is slackened!
4. Unscrew the spring cap (double-ring spanner op-
tionally available).
5. Remove the sliding ring.
6. Use pliers to remove the valve core.
7. Check that the gasket, nozzle edge and ring
groove are in perfect condition; if necessary, re-
place the entire valve core.
8. Install in reverse order.
9. Set outlet pressure.
9.2.2 Maintaining and cleaning the backflow
preventer core
Do not use solvents and/or cleaning agents contai-
ning alcohol to clean the plastic components, as this
can lead to water contamination!
Do not allow any cleaning agents to enter the envi-
ronment or the sewage system!
1. Close the shut-off ball valve on the inlet side of
the AQA therm HFB-1717 BA and the outlet side
of the AQA therm HES.
2. Depressurise the outlet side by opening the sam-
pling valve (bleed valve on the AQA therm HES).
3. Unscrew the cover of the backflow preventer
core.
4. Remove the backflow preventer core and filter.
5. Remove the filter from the backflow preventer
core.
6. Clean the filter and backflow preventer core or,
where appropriate, replace it. The backflow pre-
venter core should not be taken apart!
7. Install in reverse order
- Press the cartridge until it clicks.
8. Check that it is operating correctly.
9.2.3 Backflow preventer
1. Close the shut-off ball valve on the inlet side of
the AQA therm HFB-1717BA and the outlet side
of the mixing unit.
2. Depressurise the outlet side by opening the sam-
pling valve (bleed valve on the AQA therm HES).
3. The backflow preventer is defunct once it has
been dismantled.
4. Check that it is operating correctly.
10. Waste disposal
- Housing: zinc-resistant brass.
- Drainage connection, backflow preventer core,
valve core, mechanical parts of the mixing unit
and spring cap: high-grade plastic.
- Diaphragm: EPDM, reinforced fabric.
- Seals: NBR and EPDM.
- Setpoint spring: spring steel.
- Fine filter: stainless steel.
- Cartridge (HRC, SRC): polypropylene (can be
disposed of in normal waste).
- Batteries, electronic
6280_EBA AQA therm HFB_HES_HWG_313660-5.indd 20
24.09.15 09:09
